Effectively you are doing an ICO capped at 5 BTC per day if the price for each ticket won't change. The total fund to raise is 5*40 = 200 BTC.
As you can see in this block https://bts.ai/block/53159405 bot-11 account “registered” 1 RUDEX.LOTTERY and got a transaction number TXID of d60c7ce9467043cf81acd5fdb1c5bc851d20faed.
If this value is divided by modulo 5 (number of combinations), then the remainder of the division will be the combination number of this ticket. You can verify the division remainder using, for example, the following service: https://defuse.ca/big-number-calculator.htm
In our case you need to insert the following line into the calculator 0xd60c7ce9467043cf81acd5fdb1c5bc851d20faed % 5, which is equal to the value of 4, which is a combination for 30 GPH token win.
Just for the info:
It is very simple for a skilled programmer to "mine" (brute force) the TXID and only submit the transaction to the blockchain if 4 is the remainder, with no extra cost.
Guess how many times you need to try to get your desired value if the chance is 20% every time. It is 5 times on average.
IMHO the design is stupid.
Good luck anyway.